Naying An

Bio: Naying An is an academic researcher from Shanghai University. The author has contributed to research in topics: Synchrotron & Selective laser melting. The author has co-authored 1 publications.

Application of Synchrotron X-Ray Imaging and Diffraction in Additive Manufacturing: A Review

Abstract: Additive manufacturing (AM) is a rapid prototyping technology based on the idea of discrete accumulation which offers an advantage of economically fabricating a component with complex geometries in a rapid design-to-manufacture cycle. However, various internal defects, such as balling, cracks, residual stress and porosity, are inevitably occurred during AM due to the complexity of laser/electron beam-powder interaction, rapid melting and solidification process, and microstructure evolution. The existence of porosity defects can potentially deteriorate the mechanical properties of selective laser melting (SLM) components, such as material stiffness, hardness, tensile strength, and fatigue resistance performance. Synchrotron X-ray imaging and diffraction are important non-destructive means to elaborately characterize the internal defect characteristics and mechanical properties of AM parts. This paper presents a review on the application of synchrotron X-ray in identifying and verifying the quality and requirement of AM parts. Defects, microstructures and mechanical properties of printed components characterized by synchrotron X-ray imaging and diffraction are summarized in this review. Subsequently, this paper also elaborates on the online characterization of the evolution of the microstructure during AM using synchrotron X-ray imaging, and introduces the method for measuring AM stress by X-ray diffraction (XRD). Finally, the future application of synchrotron X-ray characterization in the AM is prospected.

Review: The Metal Additive-Manufacturing Technology of the Ultrasonic-Assisted Wire-and-Arc Additive-Manufacturing Process

Abstract: Ultrasonic-assisted wire–arc additive manufacturing (WAAM) can refine microstructures, enhancing performance and improving stress concentration and anisotropy. It has important application prospects in aerospace, weaponry, energy, transportation, and other frontier fields. However, the process parameters of ultrasonic treatment as an auxiliary technology in the WAAM process still have an important impact on product performance indicators, such as the amplitude of the ultrasonic tool, the distance between the points of action of the product, and the scanning speed. The number of ultrasonic impacts influences the performance indexes. Therefore, these parameters must be optimized. This paper describes the advantages and the defects of WAAM components, as well as the principle and development status of ultrasonic treatment technology. Subsequently, this paper also briefly describes how ultrasonic-assisted technology can refine the crystal and improve the mechanical properties of WAAM components. Finally, we review the influence of process parameters (such as ultrasonic amplitude, application direction, and impact times) on the product materials. In this paper, a comprehensive optimization method for ultrasonic parameters is proposed to improve the mechanical properties of WAAM components.